System and method for spectrum sharing and interference management between wireless systems

ABSTRACT

A method of allocating resources in a first wireless system, wherein the first wireless system shares a frequency spectrum with a second wireless system, is described. The method comprises detecting a level of interference to the second wireless system caused by the first wireless system on a first frequency within the spectrum; determining if transmission on the first frequency should be restricted based on the level of interference; and restricting transmissions in the first system on the first frequency if it was determined that transmission on the first frequency should be restricted while allowing normal use of the remaining portions of the frequency spectrum to continue in the first system. A system for allocating resources in a first wireless system, wherein the first wireless system shares a frequency spectrum with a second wireless system, is also described.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/069,565, filed Mar. 14, 2016, which claims the benefit of U.S.Provisional Application Ser. No. 62/132,669, filed Mar. 13, 2015, eachof which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present disclosure generally relates to spectrum sharing andinterference management between wireless systems.

BACKGROUND

The proliferation of smartphones and other wireless devices has led tothe ever-increasing demand for wireless spectrum. In an effort toameliorate this problem, the U.S. Federal Communications Commission(“FCC”) has opened up the 3550-3700 MHz band (“3.5 GHz band”), which hastraditionally been reserved for military use, for shared-spectrum use.Shared-spectrum use has also been contemplated for the 1695-1710 MHz,1755-1780 MHz, and 2155-2180 MHz bands (collectively, the “AWS-3” bands)during a transitional period when federal incumbent systems relocate outof the bands. When spectrum is shared, some mechanism must be adopted toensure users of the same spectrum do not interfere with each other andusers with higher priorities are guaranteed access to the spectrum in asituation of a conflict.

Using the 3.5 GHz band as an example, to protect existing users of theband, a three-tiered model has been adopted by the FCC, as Illustratedin FIG. 1. As shown in the figure, incumbent access (IA) users, shown asfederal and non-federal incumbent systems, are positioned at the toptier and have the highest priority. One or more Spectrum Access Systems(‘SASs’) may facilitate spectrum sharing between the Incumbent users andpublic users, such as commercial cellular operators, emergency vehicles,police, etc. Among the public users, some may obtain higher priorityunder a Priority Access License (“PAL”), while others may operate underGeneral Authorized Access (“GAA”), i.e., without a license, but with thelowest priority. A spectrum access system (“SAS”) may facilitate thethree-tiered model by ensuring that devices in a lower-priority accesstier do not interfere with those in a higher-priority tier. The SAS mayaccomplish this by monitoring interference and dynamically assigningfrequency bands to devices operating in the shared spectrum. It will beunderstood that a “frequency” may be a frequency band, a frequencychannel, or a channel, and vice versa.

The public use devices, i.e., the PAL and GAA devices, may each operateor run a communications system and communicate with end user devices,such as smartphones or other portable devices carried by end users, viaany suitable wireless communication technologies or standard protocols,such as Long Term Evolution (LTE), Wideband Code Division MultipleAccess (WCDMA), Global System for Mobile Communications (GSM), etc. TheSAS coordinates and manages spectrum sharing among the incumbents, thePAL systems, and the GAA systems, by assigning spectrum to the PAL andGAA devices as requested for use by the respective systems, while at thesame time ensuring that the PAL and GAA devices and systems do notinterfere with the incumbents, that the GAA systems do not interferewith the incumbents and the PAL systems, and that the PAL users do notinterfere with each other.

When the systems are in close proximity with one another, functions ofthe SAS alone may be insufficient to avoid harmful interference.Assistance from the individual systems may be necessary to ensureinterference stays at a permissible level.

SUMMARY

The present disclosure is directed to systems and methods for spectrumsharing and interference management between wireless systems.

Consistent with at least one disclosed embodiment, a method is disclosedfor allocating resources in a first wireless system, wherein the firstwireless system shares a frequency spectrum with a second wirelesssystem. In one embodiment this may be accomplished by detecting a levelof interference to the second wireless system caused by the firstwireless system on a first frequency within the spectrum; determining iftransmission on all or a portion of the first frequency should berestricted based on the level of interference; and restrictingtransmissions in the first system on the first frequency if it wasdetermined that transmission on all or a portion of the first frequencyshould be restricted while allowing normal use of the remaining portionsof the frequency spectrum to continue in the first system.

Consistent with at least one disclosed embodiment, a wirelesscommunications system is disclosed for allocating resources in a firstwireless system. In one embodiment this may be accomplished with a firstwireless system that shares a frequency spectrum with a second wirelesssystem; at least one sensor configured to detect a level of interferenceto the second wireless system caused by the first wireless system on afirst frequency within the spectrum; and at least one processorconfigured to receive the level of interference, determine iftransmission on all or a portion of the first frequency should berestricted based on the level of interference, and generate at least oneinstruction for the first system to restrict transmissions therein onthe first frequency if it was determined that transmission on the firstfrequency should be restricted while allowing use of the remainingportions of the frequency spectrum to continue in the first system.

Consistent with at least one disclosed embodiment, a wirelesscommunications device is disclosed for allocating resources in a firstwireless system. In one embodiment this may be accomplished with atleast one receiver configured to receive from a sensor a level ofinterference caused by a first wireless system on a first frequencywithin a frequency spectrum to a second wireless system, wherein thefirst wireless system shares the spectrum with the second wirelesssystem; at least one processor configured to receive the level ofinterference, determine if transmission on the first frequency should berestricted based on the level of interference, and generate at least oneinstruction for the first system to restrict transmissions therein onthe first frequency if it was determined that transmission on the firstfrequency should be restricted while allowing use of the remainingportions of the frequency spectrum to continue in the first system; andat least one transmitter configured to transmit the instruction to thefirst wireless system.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute partof this specification, and together with the description, illustrate andserve to explain various embodiments.

FIG. 1 illustrates a three-tiered model adopted by the FCC for ashared-spectrum system;

FIG. 2 illustrates an exemplary shared-spectrum system for implementingmethods and systems consistent with the present disclosure;

FIG. 3 illustrates an exemplary architecture of an LTE system;

FIG. 4 illustrates an exemplary time-frequency resource grid structurefor uplink communications in accordance with an embodiment of thepresent disclosure;

FIG. 5 illustrates an exemplary use restriction of a portion ofotherwise available bandwidth, in accordance with an embodiment of thepresent disclosure; and

FIG. 6 is a flow diagram illustrating an exemplary method for allocatingresources in a shared-spectrum system, in accordance with an embodimentof the present disclosure.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings.Wherever possible, the same reference numbers are used in the drawingsand the following description to refer to the same or similar parts.While several Illustrative embodiments are described herein,modifications, adaptations and other implementations are possible. Forexample, substitutions, additions or modifications may be made to thecomponents illustrated in the drawings, and the Illustrative methodsdescribed herein may be modified by substituting, reordering, removing,or adding steps to the disclosed methods. Accordingly, the followingdetailed description is not limited to the disclosed embodiments andexamples. Instead, the proper scope is defined by the appended claims.

LTE has been widely deployed in the U.S. In a shared-spectrum system,such as the three-tiered model adopted by FCC for the 3.5 GHz band, manyPAL and GAA users will likely choose LTE as their wireless communicationstandard and their LTE systems will coexist with non-LTE systems. LTEemploys orthogonal frequency division multiplexing (OFDM) technology,where the frequency band is divided into a number of smaller orthogonalfrequency bands called subcarriers. The subcarriers may be grouped intoPhysical Radio Resource Blocks (PRBs), each containing 12 subcarriersover seven OFDM symbols. Seven OFDM symbols may comprise a 0.5millisecond slot. End user devices can be assigned the subcarriersaccording to a scheduling algorithm in the system. The term “frequency”as used in this disclosure may refer to frequency band, a singularfrequency, a subcarrier, or a group of subcarriers.

Consistent with embodiments of the present invention, an LTE systemcoexisting with other system(s) in a shared-spectrum network allocatesspectrum, subcarriers, or spectrum resources to its end users such thatthe LTE system does not utilize the spectrum used by another system inclose proximity, so as to reduce interference to the other system if theother system has a higher priority. This “blanking” or “notching” ofotherwise allocable spectrum may be permanent or dynamic. Blanking maybe used, for example, in an LTE system on PAL so that the system wouldavoid using a portion of its spectrum if that portion is used by anearby incumbent user, and in an LTE system on GAA so that the systemwould avoid using a portion of its spectrum if that portion is used bynearby Incumbent users or PAL users.

Descriptions of embodiments are provided below using the example of anLTE system and the three-tiered model adopted by the FCC, but are notlimited to such.

FIG. 2 illustrates an exemplary shared-spectrum system 200 consistentwith the present disclosure. System 200 includes a network 202 to whichall devices of the system connect, one or more LTE systems 206, non-LTEIncumbent systems (“incumbents”) 208, one or more SASs 210, and/or othernon-LTE, non-incumbent systems 212. Network 202 may comprise anysuitable network such as the Internet, a wide area network, or any othernetwork that permits exchange of information between various componentsof the system. LTE system 206 may comprise, for example, cellularnetwork base stations, emergency vehicles, or any other system that doesnot have incumbent status. In the three-tiered model shown in FIG. 1,LTE system 206 may be operating on PALs or as GAAs. In the example ofthe 3.5 GHz band, non-LTE incumbents 208 may comprise systems used bybranches of armed forces, for example, U.S. Department of Defense airsurveillance radar systems, or devices used by other governmentoperators. Non-LTE, non-incumbent systems 212 may comprise, for example,Wi-Fi networks or other telecommunication networks using Wideband CodeDivision Multiple Access (WCDMA), Global System for Mobile Communication(GSM), or any other suitable technology. SAS 210 coordinates and managesspectrum sharing among non-LTE incumbents 208, LTE system 206, andnon-LTE, non-incumbent systems 212 by assigning spectrum to LTE system206 as requested, while at the same time ensuring that the LTE system206 and non-LTE, non-incumbent systems 212 do not interfere with non-LTEincumbents 208. SAS 210 may facilitate spectrum sharing by notifying LTEsystem 206 and non-LTE, non-incumbent systems 212 what frequencies theymay operate on, when they should vacate certain frequencies, or whatpower level they may transmit at. All of the LTE system 206, incumbentnon-LTE systems 208, SASs 210, and non-LTE, non-incumbent systems 212may include necessary components to facilitate wireless communicationamong them. Such components may include antennas, transmitters,receivers, and/or transceivers. They may also include processors forprocessing and generating signals.

LTE system 206 may communicate with end user devices, or user equipment(“UE”), such as smartphones or other portable devices carried by endusers. FIG. 3 illustrates an exemplary architecture of LTE system 206 byreference to an exemplary LTE system 300. LTE system 300 may include enduser devices or UE 310 (310 a, 310 b, 310 c), an Evolved UniversalTerrestrial Radio Access Network (E-UTRAN) 304, and an evolved packetcore (EPC) 306. E-UTRAN 304 may include one or more base stations 302(302 a, 302 b), also referred to as eNode B or eNB, which control radiocommunications of UE 310 within their respective cells. EPC 306communicates between E-UTRAN 304 and external packet data networks 308(308 a, 308 b, etc.) Each eNB 302 may Include a Resource Scheduler 316that assigns frequency resources to UE 310. One flavor of the LTEstandards is the so-called frequency division duplexing (FDD), wheredifferent frequency bands are assigned for communications from UE to eNB(uplink) and communications from eNB to UE (downlink). LTE standardsalso provide for use of the same frequency band on both the uplink anddownlink but at alternating times, a scheme referred to as time divisionduplexing (TDD).

Using FDD LTE as an example, FIG. 4 shows a type-1 time-frequencyresource grid structure 400 for normal LTE FDD uplink communications,where the horizontal axis Indicates time and the vertical axis Indicatesfrequency. Type-2 time-frequency resource grid structure, not shown, maybe used for normal LTE TDD uplink communications. In the exemplarytype-1 resource grid structure shown in FIG. 4, the frequency band isdivided into a number of 15 kHz orthogonal narrower frequency bands orsubcarriers 402. A time frame 404 of ten milliseconds is also definedfor uplink transmissions. Each time frame 404 may be divided into timeslots 406 that are each 0.5 milliseconds. Two slots 406 make up a1-millisecond subframe 408. Each time slot 406 is further divided intoseven symbol units 410.

Resources in the form of subcarriers and symbol units are assigned forUE 310 to transmit to base stations 302 on the uplink. The smallestassignable block of resources, referred to as the physical radio block(PRB), labeled in the figure as 412, comprises, for example, 12subcarriers with a total of 180 kHz bandwidth spanning over one timeslot 406 or seven symbol units 410. Thus, a 10 MHz frequency bandcontaining a 1 MHz guard band has 9 MHz bandwidth divided into 50 (=9MHz/180 kHz) PRBs in parallel. Different UEs 310 may transmit overdifferent PRBs across the frequency band at the same time, and one UE310 may transmit on multiple PRBs consecutive in frequency. Resourcescheduler 316 is responsible for allocating PRBs to UE 310 within thecorresponding cell based on need and availability. The uppermost andlowermost portions, or the edges, of the band are generally designatedas Physical Uplink Control Channels (PUCCHs) 414. Other portions of theband may be designated as Physical Uplink Shared Channels (PUSCHs) 416.PUCCHs 414 are used to carry uplink control information, and PUSCHs 416are used for transmitting UE data.

Consistent with embodiments of the present disclosure, when operationsof LTE system 206 cause harmful interference to a non-LTE incumbentsystem 208 or a higher priority system, either because they are in closephysical proximity or for any other reason, it may be necessary for theLTE system to restrict, eliminate, notch, or blank interfering signals.FIG. 5 illustrates an example where use of a portion of the otherwiseavailable bandwidth is restricted so resource scheduler 316 does notassign PRBs within the portion of the bandwidth to UE 310 in the uplink.As shown in FIG. 5, PRBs 502, 504, 506, and 508 in the edge portions ofthe frequency band are allocated for PUCCH transmission. Resourcescheduler 316 assigns a minimum of 2 PRBs to a piece of UE for PUSCHtransmission. For example, PRBs 510 and 512 are allocated to user 1 andPRBs 514 and 516 are allocated to user 2. A certain frequency within thePUSCH region of the frequency band may be used by higher-prioritysystems (such as incumbent systems 208). To avoid harmful interference,resource scheduler 316 may restrict the use of PRBs via blocking orblanking or notching so that UE on LTE system 206 does not transmit onthose PRBs at or around the certain frequency. In one aspect, resourcescheduler 316 may block the use of a PRB such that no UE may transmit onthe PRB. Alternatively, resource scheduler 316 may Instruct UE 310 toreduce transmission power to below a harmful level. In one aspect,resource scheduler 316 may issue instructions based on Informationreceived from SAS 210 to achieve the blocking, blanking, notching, orreduced transmission power. In another aspect, SAS 210 may provideinstructions to resource scheduler 316 to block the use of a PRB. Itwill be appreciated by those skilled in the art that the blockedspectrum resource may be any smallest group of subcarriers or afrequency-time segment used by the wireless system for scheduling and isnot limited to PRBs in an LTE system. Such smallest allocable spectrumresource may be generally referred to as a “scheduling unit.”

In one aspect, the blocking or blanking or notching may be permanent, sothat LTE system 206 never uses those PRBs in the neighborhood of thefrequency used by the higher priority system and resource scheduler 316never assigns such PRBs to UE 310. In another aspect, resource scheduler316 dynamically restricts use of the PRBs within the potentiallyinterfering portion of the frequency band. In the example shown in FIG.5, resource scheduler 316 blocks a region 518 over a subframe and aplurality of PRBs and may unblock the use of the PRBs in a subsequentsubframe. Resource scheduler 316 may continue to assign other portionsof the bandwidth to UE 310 for normal use.

In one aspect, resource scheduler 316 communicates with SAS 210 todetermine if any portion of the uplink frequency band is used by ahigher priority system such as an incumbent user and if transmissionsfrom UE 310 in the cell cause significant interference to thehigher-priority system, to receive Instructions as to how to use anuplink frequency, or to confirm that use of an uplink frequency ispermitted. In that regard, system 200 may further include one or moresensors (not shown) that sense spectrum usage and report the sensedInformation to SAS 210 to facilitate detection of frequency use byvarious systems. The sensors may comprise any device suitable fordetecting wireless transmissions and determining spectrum usage, such asantennas, radars, etc. The sensors may be distributed over the areacovered by the network, either installed within systems 206, 208, 212,or separately from those devices. The sensors may be mobile or in fixedlocations. Alternatively, end user devices may also sense theenvironment and report measurements to the systems 206, 208, and/or 212,which may then report the Information to SAS 210. Existing sensors, suchas those for sensing and detecting incumbent users, may also gather andforward frequency use information to SAS 210.

Information gathered from the sensors may identify devices or systems,the relative priority (i.e., incumbent vs. PAL vs. GAA), frequencyranges used by the systems, the time period of such use, transmissionpower, and/or a tolerance level for interference. SAS 210 communicatessuch information to LTE system 206, and LTE system 206 determineswhether and when to restrict use of certain PRBs that might causeharmful interference to a system with a higher priority of use than LTEsystem 206. Resource scheduler 316 may simply decide to permanentlyblock the use of all PRBs within the entire frequency spectrum used by ahigher-priority system. But that may be inefficient. Interference variesacross the frequency spectrum and maybe only a small portion of thespectrum is more susceptible to harmful interference, in which case onlythe use of PRBs within the small portion need to be blocked orrestricted. SAS 210 or LTE system 206 may calculate the level ofinterference and determine that potential interference is harmful if itexceeds a certain threshold level generated from empirical data orprovided by SAS 210. Alternatively, or in addition, the higher-prioritysystem's use of the spectrum may be temporary, in which case the use ofPRBs that might cause harmful interference only needs to be blocked orrestricted for a limited period of time. Resource scheduler 316 may alsoemploy other criteria in deciding whether and when restricting orblocking the use of PRBs should take place, such as the absolutepriority level of the incumbent system that might be harmed by theinterference. For example, if LTE system 206 is a GAA system, resourcescheduler 316 may give incumbent systems 208 a higher level of deferencethan PAL users, such that a lower threshold will be used for blocking orrestricting use of PRBs that might cause harmful interference toincumbent users than to PAL users.

Determination of the level of possible interference and/or whetherblocking or restricting the use of PRBs is necessary may be performed byeither a SAS 210, or a component within the LTE system 206 based on theinformation received from the SAS 210. SAS 210 generally has access tomuch more frequency use data, and can perform necessary computation on aserver or in the cloud, and provide the computation results to LTEsystem 206. SAS 210 can also provide sufficient frequency use data toLTE system 206 such that a component thereof (such as a processor withineNB 302) can perform the computation.

Proper operation of LTE system 206 requires PUCCH assignment at alltimes. Therefore, resource scheduler cannot block PUCCHs 502. In theevent transmissions on the PRBs for PUCCH cause harmful interference toa higher-priority system, resource scheduler 316 may allocate adifferent set of PRBs for PUCCH and restrict or block the use of thePRBs originally assigned for PUCCH. This may be called an“over-provisioned PUCCH.”

Consistent with embodiments of the present disclosure, resourcescheduler 316 may include necessary hardware and/or software thatinteracts with SAS 210 to gather frequency use or Interference data anddetermines, based on the gathered information, whether certainsubcarriers within a time frame should be blanked. The scheduling ofPRBs according to the above-described blocking/blanking/notching schememay be easily implemented as a software update in resource scheduler316.

FIG. 6 is a flow diagram illustrating an exemplary method 600 consistentwith embodiments of the present disclosure. At Step 602, frequency usedata is gathered for the frequency band used by LTE system 206 andparticular frequency or frequencies are identified if they are used byanother system (such as non-LTE incumbent system 208) with a higherpriority than LTE system 206 in the shared-spectrum system. Thegathering of the data at Step 602 may be performed by SAS 210 incoordination with other devices or components in the system, asdescribed above.

At Step 604, the level of potential interference on a particularfrequency from LTE system 206 to the other system is detected. Thisdetection may be performed by LTE system 206 (such as resource scheduler316) based on frequency use data provided by SAS 210, or by SAS 210, orby both.

At Step 606, a determination is made as to whether transmissions on theparticular frequency should be reduced. The determination may be made bythe SAS 210, or LTE system 206 (such as resource scheduler 316) based onInformation received from SAS 210. The determination may comprisedetermining whether the interference level exceeds a threshold. If so,transmissions on the particular frequency or corresponding PRBs may bereduced (Step 608). In one aspect, transmission power from UE on thecell must be reduced to a permissible level or lower. Alternatively,resource scheduler 316 may simply block transmissions on the particularfrequency or corresponding PRBs completely.

As discussed above and as shown in FIG. 6, method 600 may repeat thedetermination of whether transmissions on a frequency or correspondingPRBs should be blocked or reduced to achieve a dynamic and efficient PRBschedule in LTE system 208.

Although the above descriptions use LTE as an example, it should beapparent to one skilled in the art that the system and method consistentwith the present disclosure may be implemented with any multi-carriersystem or the like that allows division of the frequency spectrum intosubcarriers, or smaller frequency bands, and assigns spectrum on thebasis of the subcarriers or smaller frequency bands. The schedulinggranularity in LTE systems is at the PRB level. This method can begeneralized to other radio technologies with different scheduling units,such as individual or a group of subcarriers or frequency bands over anysuitable time periods.

The systems and methods described above may be implemented by anyhardware, software, or a combination of hardware and software having theabove-described functions. The software code, either in its entirety ora part thereof, may be stored in a computer readable memory.

While several implementations have been provided in the presentdisclosure, it should be understood that the disclosed systems andmethods may be implemented in many other specific forms withoutdeparting from the scope of the present disclosure. The present examplesare to be considered as illustrative and not restrictive, and theintention is not to be limited to the details given herein. For example,the various elements or components may be combined or integrated inanother system or certain features may be omitted, or not implemented.

Also, techniques, systems, subsystems, and methods described andIllustrated in the various implementations as discrete or separate maybe combined or integrated with other systems, modules, techniques, ormethods without departing from the scope of the present disclosure.Other items shown or discussed as coupled or directly coupled orcommunicating with each other may be indirectly coupled or communicatingthrough some Interface, device, or intermediate component, whetherelectrically, mechanically, or otherwise. Other examples of changes,substitutions, and alterations are ascertainable by one skilled in theart and could be made without departing from the spirit and scopedisclosed herein.

While the above detailed description has shown, described, and pointedout the fundamental novel features of the disclosure as applied tovarious implementations, it will be understood that various omissionsand substitutions and changes in the form and details of the systemillustrated may be made by those skilled in the art, without departingfrom the intent of the disclosure.

What is claimed is:
 1. A method of allocating resources in a firstwireless system, wherein the first wireless system shares a frequencyspectrum with a second wireless system, the method comprising: receivinga level of interference to the second wireless system caused by thefirst wireless system on a first frequency within the frequencyspectrum, the level of interference having been detected by at least onesensor separate from the first wireless system; determining iftransmission on the first frequency in the first wireless system shouldbe restricted based on the level of interference; and restrictingtransmissions on the first frequency in the first wireless system if itwas determined that transmission on the first frequency should berestricted, wherein the second wireless system is a non-cellularwireless system.
 2. The method of claim 1, wherein the first wirelesssystem schedules signal transmissions by allocating scheduling units,where a scheduling unit is a frequency-time resource.
 3. The method ofclaim 2, wherein restricting transmission on the first frequencycomprises restricting transmission on the corresponding schedulingunits.
 4. The method of claim 1, wherein the first wireless system is anLTE wireless system, the frequency spectrum is divided into a pluralityof orthogonal subcarriers, wherein the first wireless system schedulessignal transmissions based on physical resource blocks (PRB), each PRBbeing a frequency-time resource containing one or more subcarriers overa time period, and wherein the first frequency corresponds to one ormore PRBs.
 5. The method of claim 4, wherein the one or more PRBscorresponding to the first frequency carry physical uplink sharedchannel (PUSCH) transmissions.
 6. The method of claim 4, wherein the oneor more PRBs corresponding to the first frequency carry physical uplinkcontrol channel (PUCCH) transmissions.
 7. The method of claim 1, whereinrestricting transmissions in the first wireless system on the firstfrequency comprises blocking transmission on the first frequency.
 8. Themethod of claim 1, wherein restricting transmissions in the firstwireless system on the first frequency comprises instructing one or moredevices in the first wireless system to reduce the power oftransmissions on the first frequency.
 9. The method of claim 1, whereinrestricting transmissions in the first wireless system on the firstfrequency is for a limited period of time.
 10. The method of claim 1,wherein the second wireless system is an incumbent military use network.11. The method of claim 1, further comprising detecting frequency useover the frequency spectrum by a second wireless system prior toreceiving the level of interference to the second wireless system. 12.The method of claim 11, further comprising repeating the steps ofreceiving the level of interference, determining if transmission on thefirst frequency should be restricted, and restricting transmissions onthe first frequency in the first wireless system, wherein the firstfrequency may vary between repetitions.
 13. The method of claim 1,wherein determining if transmission on the first frequency should berestricted comprises determining whether the level of interferenceexceeds a threshold.
 14. A wireless communications system, comprising: afirst wireless system; a second wireless system wherein the first andsecond wireless system share a frequency spectrum, and wherein thesecond wireless system is a non-cellular wireless system; at least onesensor separate from the first wireless system and configured to detecta level of interference to the second wireless system caused by thefirst wireless system on a first frequency within the frequencyspectrum; and at least one processor configured to: receive the level ofinterference, determine if transmission on the first frequency in thefirst wireless system should be restricted based on the level ofinterference, and generate at least one instruction for the first systemto restrict transmissions on the first frequency in the first wirelesssystem if it was determined that transmission on the first frequencyshould be restricted.
 15. The system of claim 14, wherein the firstwireless system schedules signal transmissions by allocating schedulingunits, where a scheduling unit is a frequency-time resource.
 16. Thesystem of claim 15, wherein restricting transmission on the firstfrequency comprises restricting transmission on the correspondingscheduling units.
 17. The system of claim 14, wherein the first wirelesssystem is an LTE wireless system, the frequency spectrum is divided intoa plurality of orthogonal subcarriers, wherein the first wireless systemschedules signal transmissions based on physical resource blocks (PRB),each PRB being a frequency-time resource containing one or moresubcarriers over a time period, and wherein the first frequencycorresponds to one or more PRBs.
 18. The system of claim 17, wherein theone or more PRBs corresponding to the first frequency carry physicaluplink shared channel (PUSCH) transmissions.
 19. The system of claim 17,wherein the one or more PRBs corresponding to the first frequency carryphysical uplink control channel (PUCCH) transmissions.
 20. The system ofclaim 14, wherein the instruction for the first wireless system torestrict transmission on the first frequency comprises an instruction toblock transmission on the first frequency.
 21. The system of claim 14,wherein the instruction for the first wireless system to restricttransmission on the first frequency comprises an instruction for one ormore devices in the first wireless system to reduce the power of thetransmissions on the first frequency.
 22. The system of claim 14,wherein the instruction for the first wireless system to restricttransmission on the first frequency comprises an instruction to restrictthe transmission for a limited period of time.
 23. The system of claim14, wherein the second wireless system is an incumbent military usenetwork.
 24. The system of claim 14, wherein the at least one sensor isfurther configured to detect frequency use by the second wireless systemover the frequency spectrum prior to receiving the level of interferenceto the second wireless system.
 25. The system of claim 24, wherein: theat least one sensor is further configured to repeat the detection offrequency use and of the level of interference, wherein the firstfrequency may vary between repetitions; and the at least one processoris further configured to repeat the determination and repeat thegeneration of the at least one instruction, wherein the first frequencymay vary between repetitions.
 26. The system of claim 14, wherein theprocessor is further configured to perform a determination of whethertransmission on the first frequency should be restricted, wherein thedetermination is based on whether the level of interference exceeds athreshold.